Siderail apparatuses have been widely used in various applications such as with hospital beds, stretchers and other lying surfaces used in medical applications. One of the main purposes of a siderail apparatus in such applications is to secure the patient on the lying surface by diminishing the possibility of the patient accidentally falling off of the lying surface or in some case to prevent the patient from intentionally leaving the lying surface.
Most siderail apparatuses are moveable in one-way or another. This characteristic improves the flexibility and the ease of use of a siderail apparatus in various ways. The main moving feature of a siderail apparatus is the ability to move the siderail to a deployed position when patient security is needed and to a stowed position when needed for administering patient care or to permit the patient to get on or off the lying surface.
There are several prior art references that disclose the use of siderail apparatuses used with lying surfaces as beds. For example, U.S. Pat. Nos. 6,389,622, 6,564,404, 6,691,345 and 5,715,548 disclose different moveable siderail apparatuses used with hospital or medical type beds.
U.S. Pat. No. 6,389,622 to Yu et al. discloses a hospital bed having siderails using a clock-type swing mechanism wherein the siderails have two arms connecting them to the bed frame with hinges so that the siderails can be raised or lowered by a rotation of about 180° from the lowered or raised position respectively. The rotation of the siderails is provided in a vertical plane parallel to the length of the bed. The arms connecting the siderail to the bed are configured as straight bars.
The outer side of the siderail is designed including inner concave grooves. If the patient wants to get on or off the bed, he may insert his fingers into the inner concave grooves to push the siderails inward and then to rotate the siderail counterclockwise or clockwise for lifting or lowering the siderail. This configuration can prevent fingers from being clamped between the siderails and the bed platform when used as intended by the patient.
This design however, has pinch points between the siderails and the arms when the siderails are moved from the raised position to the lowered position, especially when operated by a caregiver or someone located on the side of the bed. The siderail as disclosed by Yu et al. is configured to move in a single vertical plane when raised or lowered.
U.S. Pat. No. 6,564,404 to Nanahara discloses a liftable siderail for a bed. The siderail is moved in a clock-type rotational movement when it is raised or lowered and this movement is in a single vertical plane parallel to the length of the bed. The arms of the liftable siderail have a parallelogrammic frame provided on the upper side, and the ends of the shorter diagonal of the frame can correspond to the connection point with the side rail and the installation point, while the ends of the longer diagonal of the frame can define protrusions.
A liftable siderail is provided which can be lifted and lowered by the pivotal rotation of support arms along the pivots, characterized by allowing the standard values of respective dimensions of the siderail to be satisfied, while allowing the bed deck height to be low and allowing the distance between the bottom of the siderail and the floor surface to remain large when the siderail is in the stored position.
This siderail design however creates pinch points between the siderails and the arms when the siderails are moved from the raised position to the lowered position, especially when operated by a caregiver or someone located on the side of the bed.
U.S. Pat. No. 6,691,345 to Nanahara discloses a lifting mechanism for liftable siderails for a bed. The invention disclosed uses a clock-type rotational movement when the siderail is raised or lowered, the movement being in a vertical plane parallel to the length of the bed. The arms of the liftable siderail are made of two straight bars connected together through hinges, to form an “elbow-type” element.
Similarly to the siderail designs discussed above, this mechanism can create several pinch points between the siderails and the arms when the siderails are moved from the raised position to the lowered position, creating a safety problem for the patient or other person operating the siderail.
U.S. Pat. No. 5,715,548 to Weismiller et al. discloses a moveable siderail mechanism for a bed. The siderail is designed so that when the siderail is lowered from a higher position, it is moved closer to the centre of the bed having the top of the siderail beneath the sleeping surface. This operation is achieved with by two separate and distinct movements, namely the vertical movement of the siderail and the transverse movement of the siderail. The siderails are moved from the raised position to the lowered position, and vice-versa, through a pivotal movement in a vertical plane that is substantially perpendicular to the length of the bed, resulting in a “wing-type” movement. Each siderail requires a relatively wide lateral space on each side of the bed during operation.
Based on the current state of the art, there are several problems with the siderail apparatuses used in beds or the like.
For example, a problem arising from the existing siderail mechanisms used in medical beds which allow any lateral movement is that typically there is a multiple step operation of the siderail to move it from a raised position to a lowered position. Such an operation requires for example, three distinct actions. The user has to unlock the siderail, to engage in a movement to lower the siderail and then to engage in a movement to push the siderail towards the centre of the bed. This process requires time, effort and is inefficient. Some of the actions associated with the operation of such a device often require actions that are not ergonomic for the exertion of a significant level of effort.
Another problem arising out of the prior art related to a bed siderail is the space required for the operation of the siderail. Various existing products require significant lateral space to operate the siderail. Several of these siderail use a “wing-type” mechanism to raise and lower the siderail, using a pivotal rotation in a plane that is perpendicular to the length of the bed, therefore requiring extra lateral space. Furthermore, the operation may require the user of the siderail mechanism to move away from the bed in order to raise or lower the siderail and in some cases the user has to move the entire bed to an area with sufficient space before operating the siderail. This is a significant problem since the space in medical facilities is often limited, there are unnecessary efforts and unnecessary movement of the patient involved and requires more time to accomplish the desired function, thereby diminishing time for a health worker to dispense medical services.
A further problem with the existing siderail mechanisms and the prior art using a “clock-type” movement in a vertical plane parallel to the length of the bed is the creation of pinch points during the operation of the siderail. When such siderails are moved, angles between the support arms and the bottom-most edge of the siderail become acute thereby creating a pinch point where fingers, hands, clothing or bed sheets can get caught and cause injuries to the user and/or patient or create malfunctions of the siderail mechanism.
The size, particularly the width, of the bed is an important element for medical bed since, as mentioned previously, the room in medical facilities is often limited. To diminish this problem, it is therefore an important component in designing a siderail mechanism to minimize the width of the bed when not in use and conversely maximize the patient surface when in use.
There is therefore a need for a siderail mechanism which can overcome the deficiencies identified in the prior art. There is a need for a siderail mechanism that can reduce or eliminate pinch points between the siderail body and the support arms during movement thereof. In addition, there is a need for a siderail mechanism that can reduce the width of the overall bed when in the siderail mechanism is in a lowered or stowed position, wherein this can be provided in a single movement.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.